Ironically, however, a non-Arab led Sudan's first modern nationalist movement. In 1921 Ali Abd al Latif, a Muslim Dinka and former army officer, founded the United Tribes Society that called for an independent Sudan in which power would be shared by tribal and religious leaders. Three years later, Ali Abd al Latif's movement, reconstituted as the White Flag League, organized demonstrations in Khartoum that took advantage of the unrest that followed Stack's assassination. Ali Abd al Latif's arrest and subsequent exile in Egypt sparked a mutiny by a Sudanese army battalion, the suppression of which succeeded in temporarily crippling the nationalist movement. 

In the 1930s, nationalism reemerged in Sudan. Educated Sudanese wanted to restrict the governor general's power and to obtain Sudanese participation in the council's deliberations. However, any change in government required a change in the condominium agreement. Neither Britain nor Egypt would agree to a modification. Moreover, the British regarded their role as the protection of the Sudanese from Egyptian domination. The nationalists feared that the eventual result of friction between the condominium powers might be the attachment of northern Sudan to Egypt and southern Sudan to Uganda and Kenya. Although they settled most of their differences in the 1936 Treaty of Alliance, which set a timetable for the end of British military occupation, Britain and Egypt failed to agree on Sudan's future status. 

Nationalists and religious leaders were divided on the issue of whether Sudan should apply for independence or for union with Egypt. The Mahdi's son, Abd ar Rahman al Mahdi, emerged as a spokesman for independence in opposition to Ali al Mirghani, the Khatmiyyah leader, who favored union with Egypt. Coalitions supported by each of these leaders formed rival wings of the nationalist movement. Later, radical nationalists and the Khatmiyyah created the Ashigga, later renamed the National Unionist Party (NUP), to advance the cause of Sudanese-Egyptian unification. The moderates favored Sudanese independence in cooperation with Britain and together with the Ansar established the Umma Party. 
 

The Road to Independence

As World War II approached, the SDF assumed the mission of guarding Sudan's frontier with Italian East Africa (present-day Ethiopia). During the summer of 1940, Italian forces invaded Sudan at several points and captured Kassala. However, the SDF prevented a further advance on Port Sudan. In January 1941, the SDF, expanded to 20,000 troops, retook Kassala and participated in the British offensive that routed the Italians in Eritrea and liberated Ethiopia. Some Sudanese units later contributed to the British Eighth Army's North Africa victory. 

In the immediate postwar years, the condominium government made a number of significant changes. In 1942 the Graduates' General Conference, a quasi-nationalist movement formed by educated Sudanese, presented the government with a memorandum that demanded a pledge of self-determination after the war to be preceded by abolition of the "closed door" ordinances, an end to the separate curriculum in southern schools, and an increase in the number of Sudanese in the civil service. The governor general refused to accept the memorandum but agreed to a governmentsupervised transformation of indirect rule into a modernized system of local government. Sir Douglas Newbold, governor of Kurdufan Province in the 1930s and later the executive council's civil secretary, advised the establishment of parliamentary government and the administrative unification of north and south. In 1948, over Egyptian objections, Britain authorized the partially elected consultative Legislative Assembly representing both regions to supersede the advisory executive council. 

The pro-Egyptian NUP boycotted the 1948 Legislative Assembly elections. As a result, pro-independence groups dominated the Legislative Assembly. In 1952 leaders of the Umma-dominated legislature negotiated the Self-Determination Agreement with Britain. The legislators then enacted a constitution that provided for a prime minister and council of ministers responsible to a bicameral parliament. The new Sudanese government would have responsibility in all areas except military and foreign affairs, which remained in the British governor general's hands. Cairo, which demanded recognition of Egyptian sovereignty over Sudan, repudiated the condominium agreement in protest and declared its reigning monarch, Faruk, king of Sudan. 

After seizing power in Egypt and overthrowing the Faruk monarchy in late 1952, Colonel Muhammad Naguib broke the deadlock on the problem of Egyptian sovereignty over Sudan. Cairo previously had linked discussions on Sudan's status to an agreement on the evacuation of British troops from the Suez Canal. Naguib separated the two issues and accepted the right of Sudanese self-determination. In February 1953, London and Cairo signed an Anglo-Egyptian accord, which allowed for a three-year transition period from condominium rule to self-government. During the transition phase, British and Egyptian troops would withdraw from Sudan. At the end of this period, the Sudanese would decide their future status in a plebiscite conducted under international supervision. Naguib's concession seemed justified when parliamentary elections held at the end of 1952 gave a majority to the pro-Egyptian NUP, which had called for an eventual union with Egypt. In January 1954, a new government emerged under NUP leader Ismail al Azhari. 
 

The South and the Unity of Sudan

During World War II, some British colonial officers questioned the economic and political viability of the southern provinces as separate from northern Sudan. Britain also had become more sensitive to Arab criticism of the southern policy. In 1946 the Sudan Administrative Conference determined that Sudan should be administered as one country. Moreover, the conference delegates agreed to readmit northern administrators to southern posts, abolish the trade restrictions imposed under the "closed door" ordinances, and allow southerners to seek employment in the north. Khartoum also nullified the prohibition against Muslim proselytizing in the south and introduced Arabic in the south as the official administration language. 

Some southern British colonial officials responded to the Sudan Administrative Conference by charging that northern agitation had influenced the conferees and that no voice had been heard at the conference in support of retaining the separate development policy. These British officers argued that northern domination of the south would result in a southern rebellion against the government. Khartoum therefore convened a conference at Juba to allay the fears of southern leaders and British officials in the south and to assure them that a postindependence government would safeguard southern political and cultural rights. 

Despite these promises, an increasing number of southerners expressed concern that northerners would overwhelm them. In particular, they resented the imposition of Arabic as the official language of administration, which deprived most of the few educated English-speaking southerners of the opportunity to enter public service. They also felt threatened by the replacement of trusted British district commissioners with unsympathetic northerners. After the government replaced several hundred colonial officials with Sudanese, only four of whom were southerners, the southern elite abandoned hope of a peaceful, unified, independent Sudan. 

The hostility of southerners toward the northern Arab majority surfaced violently when southern army units mutinied in August 1955 to protest their transfer to garrisons under northern officers. The rebellious troops killed several hundred northerners, including government officials, army officers, and merchants. The government quickly suppressed the revolt and eventually executed seventy southerners for sedition. But this harsh reaction failed to pacify the south, as some of the mutineers escaped to remote areas and organized resistance to the Arab-dominated government of Sudan.